What distro are you running? Debian or Ubuntu (and what kernel version)? Based on your reply in the Ubuntu thread I assume we're talking about Device-2. These devices all have drivers loaded for them loaded (snd_rn_pci_acp3x for Device-2) so there shouldn't be any issue with output. Have you verified it isn't a hardware issue? Looking at the source tree, this driver hasn't had any contribution in about 2 years, so it's unlikely to me that a recent change (or the lack of it being finished) is the issue, I would put my money on it being something in userspace.
P.S. I'm not sure what you mean by experimental branch. Linux doesn't have any concept of that. Assuming we're talking about Linus' upstream repo, AFAIK there is only kernel releases and RCs. No "experimental" version unless you're compiling directly from master.
P.S. I'm not sure what you mean by experimental branch. Linux doesn't have any concept of that. Assuming we're talking about Linus' upstream repo, AFAIK there is only kernel releases and RCs. No "experimental" version unless you're compiling directly from master.